The present invention relates generally to phased array antenna systems and, more particularly, to systems having compact, low-cost transmitter-receiver modules housed for location closely adjacent and for connection with active, radiating antenna elements.
Radar and communications systems frequently require antenna arrays for long-range detection and communication. Such antenna systems are frequently quite large and because of their large size are not manipulatable to direct radiant energy for scanning and search purposes. Such large arrayed antenna systems have included means for shifting the phase of the signals directed to the individual radiators of the array, to vary the polarization of the radiated energy, to create well-defined, directed beams of radiated energy, to concentrate the radiated power for longdistance detection and communication, and to provide a steerable beam. Individual transmitters and receivers have been used for each radiator in the array to develop high transmitting power from a single antenna through the total effect of the individual smaller power transmission of each radiator element and its associated transmitter. In such an active, phased array antenna system, it is desirable that both the transmitted signal and the received signal be amplified for each antenna element in the array. Such antenna systems provide improved signal-to-noise ratios and efficiency and more effective radiated power compared to systems which do not provide amplification for each antenna element. In many prior systems, the cost and size of the individual transmit/receive apparatus prevented their use in very large, multi-element, phased array systems.
U.S. Pat. Nos. 3,307,188; 3,130,410; and 4,258,363 disclose antenna array systems in which each radiating element in the array includes an associated transmitter/receiver. None of these systems, however, discloses a fully integrated, compact, low-cost module adapted for incorporation into large, phased array radars, for physical positioning closely adjacent the radiating elements of the array, and for marked improvement in the noise, gain and radiated power characteristics of the system.